A grassroots organization called Science Debate 2008 drew up 14 questions on science and technology issues for the presidential campaign. See what Obama and McCain have to say.

— Is there a problem?The best case for GOP presidential candidate John McCain's maverick status could be made by pointing to his stands on two traditional hot-button scientific issues: stem cells and global warming.

Like his Democratic rival, Barack Obama, McCain favors expanding federal support for embryonic stem cell research, and for years he's been proposing potentially painful programs to cut greenhouse-gas emissions.

"Their emphases are different, but when you come down to it, their policies are very similar, on paper," said Kei Koizumi, director of the R&D Budget and Policy Program at the American Association for the Advancement of Science.

That's one reason why science-related issues haven't had much visibility during this year's campaign. A bigger reason is that there are more immediate matters to worry about, ranging from the continuing financial crisis to the wars in Iraq and Afghanistan. When the markets are crashing, does it really matter what the candidates say about research spending or future innovations?

Shawn Otto, chief executive officer for ScienceDebate 2008, argues that it does. He points out that scientific and technological advancements have been the engine for half of the country's economic growth since World War II — and right now, "we're coasting on the fumes of yesterday."

"Americans are starting to get it," he told msnbc.com last week. "We're living in a world where science and technology dominate a big part of our lives."

When you dig down beneath the surface, there are actually "marked differences" in how McCain and Obama approach science and technology issues, Otto said. And as Election Day approaches, some of those differences are becoming more pronounced.

Where the candidates standHere's a look at the candidates' views on the two biggest science controversies:

Stem cells: In the Senate, Obama and McCain both supported bills that would have permitted federal funding for research using human embryonic stem cells other than the 21 pre-existing strains approved by President Bush in 2001. Bush vetoed such bills in 2006 and 2007, on the grounds that such research involves the destruction of human embryos.

Obama also has co-sponsored a bill that would ban reproductive cloning aimed at creating a child, but would allow therapeutic cloning for research purposes. In contrast, McCain says he opposes all forms of cloning.

McCain says experimental techniques that appear to give normal skin cells the regenerative properties of stem cells "raise the hope that one day this debate will be rendered academic." Obama, however, sides with most stem cell researchers and says that embryonic research should continue, "ethically and with rigorous oversight."

Some scientists worry that McCain's campaign statements have become progressively less supportive of human embryonic research. The American Medical News quoted James Thomson, a stem cell pioneer at the University of Wisconsin at Madison, as saying he was "concerned about the shift from Sen. McCain."

McCain's running mate, Alaska Gov. Sarah Palin, opposes all embryonic stem cell research, as does the Republican Party platform. But during last week's final presidential debate, McCain insisted that his views haven't changed, and he took Obama to task for airing ads suggesting that they had.

Global climate change: Starting in 2003, McCain has co-sponsored a series of bills with Sen. Joe Lieberman, I-Conn., that would set up a cap-and-trade system and take other steps aimed at reducing carbon emissions. Today, McCain supports a target of reducing greenhouse-gas output to 60 percent of 1990 levels by the year 2050. Obama favors an 80 percent reduction in the same time frame.

McCain's view that humans are partly responsible for global warming, and should do something about it, has put him at odds with the Bush White House — although Bush himself has moderated his position over the past couple of years. Palin, too, appears to have softened her stance as a climate skeptic: "I don't want to argue about the causes. ... We've got to reduce emissions," she said during her debate with Obama's running mate, Sen. Joe Biden.

Most environmentalists appreciate McCain's past efforts but say he may be falling behind the curve. "McCain's take on cap-and-trade legislation is now anachronistic, lagging well behind what's current, what's possible, and what's needed," Grist's David Roberts wrote in February.

Both candidates emphasize a mix of energy sources to take the place of fossil fuels, ranging from clean-coal technology to alternative fuels. Rhetorically, McCain tends to emphasize the expansion of nuclear power, while Obama stresses solar, wind and biofuels such as ethanol. McCain wants to end domestic ethanol subsidies as well as tariffs on ethanol imports.

Follow the moneyOn other science and technology issues, the future of the federal budget plays a crucial role.

"Sen. McCain leans toward deregulation and research-and-development tax credits that encourage corporate investment in innovation," Otto said. "Sen. Obama's philosophical approach is to focus on doubling the investment in basic research [over 10 years] through the National Institutes of Health, the National Science Foundation and other federal agencies."

Both campaigns have pledged to increase spending on basic research. Obama was a co-sponsor of the America COMPETES Act, a law that authorizes $33.6 billion to $43.3 billion in additional funds over three years for a variety of technological and educational initiatives. McCain didn't vote on the bill but has pledged to "fully fund" the act's provisions. (Actual appropriations have fallen billions of dollars short of the legislation's spending targets so far.)

McCain has hinted that most categories of federal spending would be frozen at current levels if he is elected — but one of his senior campaign advisers, Ike Brannon, told The Hill last week that research spending would be exempted from the freeze.

Ironically, the campaign's sharpest exchange over science spending hasn't focused on the billions of dollars that may or may not be spent on research, but on the $3 million that was sought (unsuccessfully) by Obama and other Illinois representatives for a new projector at Chicago's Adler Planetarium. McCain repeatedly lambasted the proposed expense as a wasteful earmark.

The focus on science-related earmarks is ironic because Congress dealt a withering blow to the Department of Energy's science programs last December, in part due to an orgy of earmarks. Scores of potential layoffs loomed over Fermilab, the country's top particle physics facility — but the crisis was averted when $62.5 million in funding was restored in June, at the urging of Obama and others in the Illinois delegation.

Space exploration: Both candidates have voiced support for NASA's plan to return to the moon by 2020, known as the Constellation Program, and both have asked the space agency to look into options for keeping its space shuttles flying past their currently scheduled retirement date of 2010.

Last week, Bush signed an authorization bill that would let NASA receive up to $20.2 billion in the current fiscal year. That figure is about $2.6 billion more than the White House requested. The extra money would go to extend shuttle operations and speed development of the shuttle's replacement, the Orion-Ares launch system.

Because the federal government is currently operating under a spending freeze, it's not yet clear just how much money NASA will really end up getting. However, both campaigns have signaled they would support spending something extra to deliver a ready-to-fly, $1.5 billion physics experiment to the international space station — and potentially shorten the gap between the shuttle's retirement and Orion's scheduled debut in 2015.

Early in the campaign, Obama suggested that the Constellation Program could be put on hold for five years in order to boost education spending. But after hearing an outcry from space advocates — and perhaps after considering Florida's role in the upcoming election — he said he would look for different ways to fund his education plan.

Science leadership: Both candidates say they would give their top science adviser Cabinet-level status, something that President Bush's adviser lacks. McCain has called for the appointment of a "science and technology adviser," while Obama wants to have a science adviser as well as a "chief technology officer" and a strengthened advisory council on science and technology.

The Bush administration has often faced criticism for putting political ideology before scientific realities, particularly on climate change, but both candidates say they will put a premium on scientific integrity and objectivity.

Obama told ScienceDebate 2008 that he has already assembled "an impressive team of science advisers, including several Nobel laureates, who are helping me shape a robust science agenda for my administration." More than 60 Nobel science laureates have signed a letter endorsing Obama.

McCain, meanwhile, points to his experience as a former chairman of the Senate Commerce, Science and Transportation Committee. "Under my guiding hand, Congress developed a wireless spectrum policy that spurred the rapid rise of mobile phones and Wi-Fi technology that enables Americans to surf the Web while sitting at a coffee shop, airport lounge or public park," he told ScienceDebate 2008.

Surprises for the next presidentHow will the current financial crisis affect the visions that both candidates have laid out? The next president will surely be more climate-conscious than the current one, but if the economic situation becomes as bleak as expected, that could pose challenges for the environmental agenda and other research initiatives.

"The key is, how much are they willing to spend on domestic programs?" Koizumi said.

There could be other surprises as well:

The next president may be surprised to find how little influence he has on the pace of innovation. Lately, Congress and private industry have played at least as much of a role as the White House in setting the nation's scientific and technological course.

An argument could be made that the last president to set a dramatic new course was John F. Kennedy, who heralded a "New Frontier" in 1960. Will the next president be able to find a new New Frontier for America in the 21st century? A solution for the world's energy problems, perhaps, or a campaign to head off a global climate crisis, or a race to return to the moon before the Chinese? A development of that magnitude would be the biggest surprise of all.